Field of the Invention
The present invention relates to a composition for agricultural or horticultural application, and a method for cultivating a plant. More precisely, the present invention relates to a composition for agricultural or horticultural application that can promote blooming and the appearance of fruit of a plant, the ripening and/or change in color of fruit before and after harvest, and so forth, and uses thereof.
Brief Description of the Related Art
In order to improve the growth of crops and the quality of fruits harvested or nuts harvested from those crops, chemical fertilizers, phytohormones, and so forth are used. However, these methods have unsolved problems concerning their influence on the environment and their cost. Amino acids are known to be environmentally friendly and inexpensive ingredients of compositions for agricultural or horticultural application. For example, a flower bud formation-promoting agent using proline as an active ingredient (Japanese Patent Laid-open (Kokai) No. 2003-48803), a plant high temperature stress resistance-imparting agent containing a branched chain amino acid such as valine or leucine (Japanese Patent Laid-open (Kokai) No. 2012-197249), a plant growth-promoting liquid fertilizer containing 18 kinds of amino acids (South Korean Patent Laid-open No. 2013-107406), a plant allelopathy effect and/or phytoalexin production-enhancing agent containing an amino acid fermentation by-product or a nucleic acid fermentation by-product (Japanese Patent Laid-open (Kokai) No. 2012-10694), and so forth, have been reported. Hydroponics of tobacco in an aqueous solution containing glutamic acid, aspartic acid, and phenylalanine have been reported to increase the content of amino acids, chlorophylls, and carotenoids in the leaves (Wu, X-P. et al., Scientia Agricultura Sinica, 2004, 37(3):357-361).
The aforementioned plant growth-promoting liquid fertilizer (South Korean Patent Laid-open No. 2013-107406) contains 0.05% of isoleucine, and the concentration thereof in a liquid to be sprinkled is 0.019 to 0.076 mM. Furthermore, Japanese Patent Laid-open (Kokai) No. 2012-10694 describes that a treatment of rice seeds with 0.2 to 20 mM isoleucine promoted production of momilactones A and B.
It is known that jasmonic acid, which is a kind of phytohormone, has physiological actions including those for topogenesis, such as the formation of flower and formation of tuber, and transcription-activating actions for genes that respond to stresses such as insect damages and diseases (New Science of Phytohormones). It has also been reported that a treatment of fruits or berries such as tomatoes and strawberries with methyl jasmonate promotes the appearance of fruit or the ripening or change in color (Liu, L., Journal of Experimental Botany, 2012, 63(16):5751-5761 and Concha, C. M. et al., Plant Physiology and Biochemistry, 2013, 70:433-444).
It is known that, in the jasmonic acid signal transduction, (+)-7-iso-JA-Ile consisting of jasmonic acid and isoleucine bound together constitutes the active type (Fonseca, S. et al., Plant Biology, 2009, 12:539-547, Fonseca, S. et al., Nature Chemical Biogogy, 2009, 5:344:350, and Wasternack, C., Annals of Botany, 2013, 111:1021-1058).
As for the relation of isoleucine and jasmonic acid, it was reported that infection of Phelipanche aegyptiaca, which is a plant parasite, in Arabidopsis thaliana cultivated on an agar medium was suppressed by a treatment of the plant with a mixture of isoleucine and methyl jasmonate, whereas a treatment with isoleucine alone was ineffective (Nun, N. B. et al., Phytoparasitica, 2009, 37(5):485-488). It has also been demonstrated that treating lima bean seedlings with immersion in a solution of a complex of leucine or isoleucine, and 1-oxoindane-4-carboxylic acid or 1-hydroxyindane-4-carboxylic acid, induces synthesis of volatile substances involved in insect resistance, and a complex of an amino acid and jasmonic acid is an intermediate of the octadecanoid signal transduction pathway (Krumm, T. et al., FEBS Letters, 1995, 377(3):523-529).
It was also reported that by treating barley leaves with immersion in a solution for inducing osmotic pressure stress (D-sorbitol, D-mannitol, polyethylene glycol 6000, and sodium chloride) increased j asmonic acid and complex of j asmonic acid and an amino acid (Kramell, R. et al., Journal of Plant Growth Regulation, 1995, 14(1):29-36).
There has also been a report concerning the influences of branched chain amino acids and so forth on growth and nutritional state of tomatoes, as well as growth, survival, and proliferation of Bemisia tabaci (Pang, S-T. et al., Chinese Journal of Eco-Agriculture, April 2013, 21(4):465-473). The concentration of isoleucine used for the treatment described in this report is 0.012 to 0.035 mM.
It has also been reported that mixed fertilizers containing various amino acids, trace ingredients, and phytohormones increase fruit ratio and crop yield of plant fruits (Chinese Patent Laid-open No. 102627498). The concentration of isoleucine used for the treatment described in this report is 1.1 to 4.3 nM.
It has also been reported that foliar spray fertilizers containing various amino acids, trace ingredients, xanthine, etc. have plant fruit-increasing effects, saccharide content-increasing effects, and so forth (Chinese Patent Laid-open No. 102285823), and that foliar spray fertilizers containing trace ingredients and various amino acids increase crop yield of Chinese cabbage (Chinese Patent No. 101891520). It has further been reported that glutamic acid increases anthocyanin of apple (Wang, L. J., Journal of Fruit Science, 2006, 23(2):157-160), and that phenylalanine increases anthocyanin of grape (Qu, J. G. et al., Sheng Wu Gong Cheng Xue Bao, 2006, 22(2):299-305). It has also been reported that methionine promotes ripening of fruits (Japanese Patent Laid-open (Kokai) No. 2007-259714).
As described above, there have been reported several findings concerning the effects of isoleucine and other amino acids on plants, but it is not known that application of a high concentration isoleucine solution by sprinkling promotes blooming and the appearance of fruit of plants, ripening of harvested fruits, and so forth.
In addition, it was reported that, when examining the influences of substitution of each of 20 kinds of amino acids for 20% of nitrate nitrogen in a nutrient solution on growth of bok choy in hydroponics, isoleucine increased nitrogen and phosphorus contents of terrestrial parts (shoots) of the plant, but it was not effective on the growth (weight of root clump) (Wang, H-J. et al., Pedosphere, 2007, 17(5):595-600).